The prospects for a two-state solution to the bitter conflict in the Middle East are being undermined by “facts on the ground” created by Israel, Palestinian divisions and the continuing “convulsions” of the Arab spring, the former British foreign secretary David Miliband is warning.

Miliband, speaking on Thursday, is the latest high-profile international figure to express alarm at the rapidly fading prospects for the creation of an independent Palestinian state alongside Israel â€“ for decades the only solution that has seemed either possible or practicable.

“The danger is that, unwittingly, by omission not commission, by cruel irony not deliberate plot, the Palestinian cause is a victim of the Arab revolts,” Miliband will argue at a charity dinner for Medical Aid for Palestinians.

“For the first time in a long time there is no ‘peace process’, not even the pretence of one. The facts on the ground are preventing that. Facts in respect of settlements. Facts in respect of Palestinian political divisions. Also facts in the air: Arabs, Americans and Europeans have their minds on other things.”

Miliband criticises the leaked views of Mitt Romney, the Republican contender in the US presidential election. “Now is not the time to say that the problem is unsolvable or that Palestinians are committed to the destruction of Israel,” he says. “That is a recipe that is not just unfair on the Palestinians. It is also dangerous for the region, including Israel.”

To revive prospects for creating a Palestinian state, Miliband calls for Gaza â€“ isolated by Israel and Egypt and cut off from the West Bank â€“ to be part of a diplomatic strategy. “Israelis and Palestinians are suspicious of each other and of promises from outside. But the need for a negotiated solution between the parties should not stymie international clarity and consensus about the endgame in terms of borders and other issues.”

Miliband also emphasises the importance of healing the rift between Fatah and Hamas. “Yours is a nationalist movement for justice and independence, not an Islamist movement for virtue and purity,” he says. “And the very real danger is that in a divided Palestine, the idea of a campaign that joins the people of Gaza and the West Bank, is lost.”

Surveying the Arab spring, the former Labour minister describes a “legitimacy crisis” of undemocratic regimes where “corruption, incompetence and kleptocracy have drained ruling elites of consent”. In a new regional power structure, Iran is assertive, Qatar pivotal, Turkey seeking a role, religious divisions important and well organised Islamist parties rising. Sectarian politics and violence are tragically on show from Libya to Syria.

And more broadly, Miliband suggests, there is a “new calculus in geopolitics”, with the US fatigued by Iraq and Afghanistan, Russia cash-rich but status-poor, China growing in wealth but vulnerable to Middle East instability because of oil dependence, and Europe consumed with its own problems.

“Leaders across the world must not lose interest,” he warns. “The fact that Palestine is not in the headlines does not mean it can be forgotten. We know there can be no justice in the Middle East without a Palestinian state. But there can be no security in the Middle East without a Palestinian state. The crowds on the streets may not be chanting about Palestine, but they have not given up in their hearts and heads.”